"Today, the GNOME Project celebrates the release of GNOME 3.6, the latest version of the popular free desktop, as well as the GNOME developer platform. GNOME 3.6 is the third major update of GNOME 3. It builds on the foundations that we have laid with the previous 3.x releases and offers a greatly enhanced experience. The exciting new features and improvements in this release include a new login experience, integrated input methods, a refresh of the message tray, support for more online accounts, improved accessibility, and many more."

August stats show almost a billion of them from Ubuntu, 959 million to be exact.
Meanwhile, the supposed alternatives stealing the momentum from Ubuntu hardly register - in particular, Mint has 11.3 M, two orders of magnitude less.

As far as very large portion of desktop Linux users are concerned, it seems that Unity is becoming the standard Linux desktop; and overall seems to work out rather fine. It certainly doesn't look like Ubuntu is among the distros which might have starter to dig their graves...